Interior: Seat belts in a '63 Cruiser

[gmax336]

I have a 1963 Cruiser that I would like to take my family out in. There are 6 of us and I need to install seat belts to accommodate everyone. Does anyone know if the seat belts sold by SI can attach two belts to one anchor?

Thanks in advance,

Jerry

[skyway]

That is how I have done all of my cars. Been a long time, but do not remember having to find longer bolts.

[JimC]

The anchor end of the seat belts in my car (which are the same type as what SI sells) look like they'd overlap just fine. Keep in mind that in an accident while "fully loaded", two people are tethered to that one anchor, potentially doubling the stress put on the anchor point. (Of course, if you have 6 people in the car, at least a couple of them would have to be fairly skinny! )

[showbizkid]

The factory only put mounting points in for 4 belts, so if you want to add two more, you'll need to use those factory points - you sure don't want to drill through the floor! The SI belts will clip right to the eye bolts, so no problem installing them at all. They use the dual-hook-end/cotter pin method of attachment.

As Jim says, though, be mindful of weight and stress levels.

[RadioRoy]

Some big fender washers on the underside of the floor will help distribute the load.

[rockne10]

The '63 Cruiser came equipped with threaded and reinforced floor anchors. I added six belts to mine with no problem. Just make certain those anchor reinforcements have not deteriorated. I had to cut one out, grind away the rusty floor residue, patch the floor and re-weld the anchor with a new reinforcement.

[JimC]

Is there a specified rating, or any writing available regarding the strength of the factory seatbelt mounting points?

A math/physics pro can correct me if my math is off, but according to my rough estimation of the impact if you are involved in a 60mph head-on crash, a 180lb person will exert about 13,000lbs of force against their seatbelts at the moment of impact. Note: I used F=ma for that. Another calculator I found online that factors in momentum and distance to stop gave me a figure of 48,000 lbs of force exerted over a 2 foot deceleration from 60 to 0 during a crash. I'm not sure if that is at the moment of impact, or the total force exerted over the length of the stop, so I'll go with the smaller number.

At any rate, even using the lesser number, and dividing it by two (because each person gets two anchor points) you're still looking at 6,500 lbs of force on that small part, at a minimum, when there's an impact. That's a lot of force. On a super rusted vehicle, I doubt they'd hold for long. Then just about double that force if you add a third set of belts. I think even those big fender washers might not be close to strong enough to hold back that much force (though they would surely help some).

[gmax336]

Fortunately, the floors are rust free. I just didn't know if the anchor bolts would accommodate two seat belts. I appreciate appreciate all the help. I''ll get those seat belts ordered.

Jerry

[showbizkid]

I think you should be fine. Jerry. The belt kits from SI come with a big ol' pair of 2.5" washers for load distribution.